What the illiterate brain tells the deaf brain

Research regarding the brain mechanisms responsible for language processing has been conducted mostly in right-handed, hearing, nontonal language speakers and generally educated adults. Studies done on populations different from this one can therefore be considered atypical (in the sense proposed by Coppens, Lebrun, and Basso in 1998) and can contribute to a better understanding of brain mechanisms involved in language processing. Comparing the brain mechanisms of illiterate versus literate subjects and deaf versus hearing subjects allows us to understand the plastic adaptations of the brain to these particular circumstances. In both these series of studies it is possible to find interesting analogies and complementary information in three different topics: interhemispheric distribution of processes, working memory related to verbal functions, and brain mechanisms involved in written language.